no margin-left for classes named no-margin-spanX in Bootstrap 2.x

no-margin-grid.less

#grid {
  .fluid (@fluidGridColumnWidth, @fluidGridGutterWidth) {
    .no-margin-spanX (@index) when (@index > 0) {
      (~".no-margin-span@{index}") { .no-margin-span(@index); }
      (~'.no-margin-span@{index}:first-child') { .no-margin-spanFirstChild(@index); }
      .no-margin-spanX(@index - 1);
    }
    .no-margin-spanX (0) {}

    .no-margin-offsetX (@index) when (@index > 0) {
      (~'.no-margin-offset@{index}') { .no-margin-offset(@index); }
      .no-margin-offsetX(@index - 1);
    }
    .no-margin-offsetX (0) {}

    .no-margin-offset (@columns) {
      margin-left: (@fluidGridColumnWidth * @columns) + (@fluidGridGutterWidth * (@columns - 1)) + (@fluidGridGutterWidth);
      *margin-left: (@fluidGridColumnWidth * @columns) + (@fluidGridGutterWidth * (@columns - 1)) - (.5 / @gridRowWidth * 100 * 1%) + @fluidGridGutterWidth - (.5 / @gridRowWidth * 100 * 1%);
    }

    .no-margin-span (@columns) {
      width: (@fluidGridColumnWidth * @columns) + (@fluidGridGutterWidth * (@columns - 1)) + @fluidGridGutterWidth;
      *width: (@fluidGridColumnWidth * @columns) + (@fluidGridGutterWidth * (@columns - 1)) - (.5 / @gridRowWidth * 100 * 1%) + (@fluidGridGutterWidth - (.5 / @gridRowWidth * 100 * 1%));
    }

    .no-margin-spanFirstChild (@columns) {
      width: (@fluidGridColumnWidth * @columns) + (@fluidGridGutterWidth * (@columns - 1));
      *width: (@fluidGridColumnWidth * @columns) + (@fluidGridGutterWidth * (@columns - 1)) - (.5 / @gridRowWidth * 100 * 1%);
    }

    .row-fluid {
      [class*="no-margin-span"] {
        .input-block-level();
        float: left;
        margin-left: 0;
      }

      // generate .no-margin-spanX and .no-margin-offsetX
      .no-margin-spanX (@gridColumns);
      .no-margin-offsetX (@gridColumns);
    }
  }
}

@media (max-width: 767px) {
  // Make all grid-sized elements block level again
  [class*="no-margin-span"],
  .uneditable-input[class*="no-margin-span"], // Makes uneditable inputs full-width when using grid sizing
  .row-fluid [class*="no-margin-span"],
  [class*="no-margin-span"]:first-child,
  .uneditable-input[class*="no-margin-span"]:first-child, // Makes uneditable inputs full-width when using grid sizing
  .row-fluid [class*="no-margin-span"]:first-child {
    float: none;
    display: block;
    width: 100%;
    margin-left: 0;
    .box-sizing(border-box);
  }
  .no-margin-span12,
  .row-fluid .no-margin-span12 {
      width: 100%;
      .box-sizing(border-box);
  }
  .row-fluid [class*="offset"]:first-child {
      margin-left: 0;
  }

  // FORM FIELDS
  // -----------
  // Make no-margin-span* classes full width
  .input-large,
  .input-xlarge,
  .input-xxlarge,
  input[class*="no-margin-span"],
  select[class*="no-margin-span"],
  textarea[class*="no-margin-span"],
  .uneditable-input {
      .input-block-level();
  }
  // But don't let it screw up prepend/append inputs
  .input-prepend input,
  .input-append input,
  .input-prepend input[class*="no-margin-span"],
  .input-append input[class*="no-margin-span"] {
      display: inline-block; // redeclare so they don't wrap to new lines
      width: auto;
  }
  .controls-row [class*="no-margin-span"] + [class*="no-margin-span"] {
      margin-left: 0;
  }
}